1. Field of the Invention
The present invention relates to a rotary-percussion power tool such as a combination hammer with a locking switch for blocking the motor switch during a chisel operation.
2. Description of the Prior Art
In the hand-held power tools which apply blows along a percussion axis and rotate thereabout, the guiding handle is vibrationally decoupled from the percussion mechanism. For a pure percussion operation, usually, the motor switch that controls the operation of the power tool motor, is blocked in its switch-on condition by a locking switch. However, this is not the case for the further drilling or rotating mode.
German Publication DE 10 034 768 discloses an electrical combination hammer drill in which the guiding handle is vibrationally decoupled with respect to the percussion mechanism. The locking switch for the motor switch is formed as a catch bracket located (at a correct handling of the power tool) in the lower handle stirrup and is hingedly supported in several points. The locking switch is connected with a rotatable operational mode selection switch. Such a solution is technologically expensive and limits the free space in the lower stirrup.
According to German Publication DE 199 37 767, a hand-held power tool which vibrates along a percussion axis, has a guiding handle provided with a motor switch and a locking switch located (at a correct handling of the power tool) on the upper handle stirrup. The locking switch blocks the motor switch in the motor switch complete switch-on condition. The blocking action of the locking switch is controlled by a displaceable rigid bar connectable with a rotatable operational mode selection switch of the percussion mechanism by an eccentric disc. The switching bar insures that blocking is possible only in the chisel operational mode but not in the drilling operational mode. This solution is likewise rather complicated.
Accordingly, an object of the present invention is a vibrating hand-held power tool provided with means that insures a technologically simple control of the locking switch for the motor switch in the vibrationally decoupled guiding handle.